The present invention relates to improvements in transmissions which can be employed with advantage in the power trains of motor vehicles to transmit torque from a prime mover (such as an internal combustion engine) to the wheels. More particularly, the invention relates to improvements in transmissions which comprise clutches, actuators, torque sensors, pulleys, belts or chains and/or other parts controlled by systems of pumps, valves and other fluid flow initiating and regulating devices.
It is often necessary to convey a fluid (e.g., oil or another hydraulic fluid) between parts which must move with and/or relative to each other, e.g., between a stationary component and a rotary component or between two components which can or must or should rotate at different speeds an/or in different directions. Transmissions wherein a conduit, a pipe, a hose or an analogous fluid conveying component must confine a stream of a fluid to flow between two spaced-apart components which can or should move relative to each other are well known in the art of power trains for motor vehicles.
It is also known to mount the fluid conveying component (hereinafter called conduit for short) in such a way that it can further serve as a means for compensating for manufacturing tolerances and/or for improper centering of one of the two spaced-apart components relative to the other component (and/or vice versa) and/or for pronounced or unanticipated or normal wear upon the spaced-apart components. In accordance with a presently known proposal, one end portion of a small-diameter conduit is introduced into a bore of one of two spaced-apart components, and the other end portion of such conduit is confined in a bore of the other of the two spaced-apart components. Each end portion is surrounded by a split-ring piston packing which is intended to seal the end portion of the respective bore. Each such packing is further intended to act as a constituent of a universal joint which enables the respective component to perform at least some stray movements (i.e., movements other than strictly angular movements) relative to the other component. Such,stray movements might be necessary to account or to compensate for certain manufacturing tolerances and/or for wear and/or for lack of accurate centering of the end portions of the conduit in the bores of the respective components. As a rule, the ability of the end portions of the conduit and of the split-ring piston packings to act as parts of a universal joint is enhanced by enlarging those portions of the bores which receive the packings.
A drawback of such connections for the end portions of the conduit is that the universal joints permit pronounced and often excessive leakage of the conveyed fluid. This can entail a penetration of a coolant or a lubricant or a force transmitting fluid agent into certain parts of a power train which should not be lubricated and/or cooled and/or wetted. Furthermore, the escaping fluid must be replaced at frequent intervals, or the reservoirzs) for such fluid must be designed to confine large quantities of oil or another fluid medium.